Gardeners are faced with all sorts of problems; weather, deer, rabbits and groundhogs to name a few.

The problem that I have in my yard can include all those things, but sometimes it’s those quiet, stealthy critters that cause unnoticed damage until it’s too late to stop it.

Skeletonized plant leaves are but a shadow of themselves, with damage throughout the leaf.

What causes the damage?

The most common reason for skeletonized leaves is caterpillar larvae feeding along the veins of the leaves.

The life cycle starts in spring with the adult laying its eggs in clusters on the underside of the leaves. The eggs are hard to spot, so once hatched the larvae begin to feed, growing larger in each of the five stages of development as they devour the leaves.

When they reach the last instar, they spin a cocoon in which it pupates and then emerges in spring as the adult that starts the life cycle again.

I noticed my rose bushes with skeletonized leaves first. These are tasty to the adults and larvae of sawflies.

These pests will also chomp on the foliage of other ornamental plants. The lacy holes appear as they follow along the veins, munching away at the tender leaves.

The veins of the leaves which aren’t as easily chewed or as tasty are all that remain.

Young caterpillars commonly feed side-by-side in groups to huddle together and stay safe while chewing on the lower leaf surface.

As the larvae grow, they tend to disperse and feed in smaller groups or individually and travel to different leaves as they spread out.

These stingless wasps are so named for the female’s saw-toothed egg-laying ovipositor.

She makes cuts along leaf edges, inserting a single egg in each pocket. Sawflies produce up to six generations annually, with the last one overwintering as pupae in the soil.

Not to be worried

The first year I was aware of this damage, I was sure our beautiful wooded lot would suffer greatly because of all the skeletonized leaves I was finding on the ground.

I learned that the damage is not a concern for healthy, established trees. There may be three generations of these pests during the summer, but control is rarely necessary.

The trees on my property did not look any worse for wear, and I was assured by two knowledgeable friends that the trees would not be affected by these pests.

Not only do sawfly larvae cause this type of damage to leaves, many varieties of caterpillar larvae will skeletonize the leaves of trees.

I also learned that same year that I was never going to have a rose garden. I couldn’t imagine that deer would eat roses, and I was wrong.

Also, lime-green larva called “rose slugs” which are also from the sawfly family, can be found on the undersides of rose leaves in spring and summer.

The damage caused begins as a delicate “skeletonizing” of leaves, creating a stained-glass appearance where small holes appear between the veins, giving a perforated, lacy appearance.

As the insect grows to its full, 3/4-inch length, the damage progresses to eating more and more of the leaves. Not only unsightly, but the removal of the green chlorophyll diminishes the plants’ ability to photosynthesize and potentially weakens the plants.

So, I gave up growing roses in my garden to save the plants from deer and larvae.

The two positives that come out of these little beasts chewing away is that they really do no harm to healthy trees and I end up with some of nature’s artwork to photograph.

Jeannie Carl is a naturalist at the Carbon County Environmental Education Center in Summit Hill. The center rehabilitates injured animals and educates the public on a variety of wildlife found in the area. For information on the Carbon County Environmental Center, visit www.carboneec.org.